Process of and apparatus for forming wire ties



April 20 1926. 1,581,794

H. DE HAVEN, JR

1 June 15, 1921 Patented Apr. 20, 1926.

UNITED STA TE PATENT or FICE.

' I HUGH DE HAVEN, JR., OF SAN FRANCISCO, CALIFORNIA, 'ASSIGNOR TO '.lII-IT MA- CHINE COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OFCALI- FORNIA.

PROCESS OF ,AND APPARATUS FOR FORMING 'WIRE TIES.

Application filed June 15, 1921. SeriaLNo. 477,645.

To all whom it may concern:

Be it known that I, HUGH of the city and county of San Francisco, Stateof California, have invented a certain new and useful Process of andApparatus for Forming Wire Ties, of'whichthe following is aspecification.

The invention relates to the art securing together wires or the ends ofa strand. of wire which is placed around a package for protecting thepackage during shipment and relates particularly to the art of twist--ing together the ends of a strand of wire which has beendrawn tautaround aj box, or twisting together two wires. i

lln the art of securing wires around boxes, the procedure has been topass a wire around the box, draw the wire tight and then twist the endsof the wire together to form a .tie or look. The desired end to-beaccomplished is to form a tie or lock which will withstand as great ifnot a greater strain than the wire and it has usually been considereddesirable to form a tie which will hold under a tension suflicientlygreat 'to rupture the wire. Attempts to reach this desired end have notculminated in uniformly successful results. The two ends of the wirestrand have been twisted together a plurality of times, but it' has beenfound that when the ends were twisted together that the wire wasweakened at the twist during the twisting operation, so that whentension was later placed onthe wire, it broke at the twist. Devices fortwisting together the ends of a wire strand surrounding a package areusually manually operated and the twist that they are designed toproduce should be of such form that the device can be easily operated byone man. The twist which can be formed most satisfactorily by ahand-operated device, is a double twist, that is, a twist formed by therotation of a twisting element through two complete revolutions. Greatdiificulty has been experienced in the past in producing a satisfactordouble twist, since if the twist is formed oosely it will unravel underten sion and if formed too tightly, the wire is so weakened durin thetwisting operation, that the twist will rupture under tension. Toovercome this difficulty, it has been proposed to form the tie of threetwists, produced by the rotation of the twisting ele- De HAvnnf, J r.,\rnent through three complete revolutions. a citizen of the UnitedStates, and a resident This, however, in a hand machine requires the useof a long, unwieldy operating lever oi'flof' a crank, either of which isobjectiona e.

In accordance with my invention, I have provided a double twist tie, oras it is termed n the art, a two-twist tie, which has a holding powernot less than the tensile strength .of the wire and which is so formedthat the a greater number of twists. l have formed two-twist ties usingNo. 13 gauge baling wire and have found that the tiss so formed are ofuniformly greater tensile strength than the wire. I have found that itis not necessarily the number of twists which determines theefiectiveness of the tie, but rather the form of the twist and after acareful analysis of the problem I have produced the very efiicient twistof the present application. a

An object of my invention, therefore, is to produce a wire tie,preferably of the twotwist type, wherein the twists are so formed thatthe tie has a tensile strength equal to or greater than the wire and inwhich the wire is not weakened so that under tension it will not breakor unravel at the twist.

A further object of the invention is to provide a process of twistingthe ends of a wire, or wires, together so that the above desirableresults will be obtained.

A further object of the invention is to provide an apparatus for formingthe desired twist.

The invention possesses other advantageous features, some of which, withthe foregoing, will be set forth at length in the following description,where I shall outline in. full the twist of my invention, the method offorming the twist'and one form of apparatus for forming it. In theaccompanying drawings I have shown one form of twist of my invention andthe apparatus for forming it, but it is to be understood that I do notlimit myself to such form of twist or apparatus, since the invention, asset forth in the Claims may be embodied in a plurality of forms. 1

Referring to said drawings:

Figure 1 is an elevation, somewhat diagrammatic, of the twisting gearheretofore generally employed, showing a twisted tie therein. 1

Fig. 2 is an elevation of one form of twisting gear of my invention.

Fig. 3 is an elevation of another form of. twisting gear of myinvention.

Fig. 4 is a side elevation of the twisting gear shown in Fig. 3, with aportion of its cooperating driving gear.

Fig. 5 is a side elevation of a twisted tic formed in the gear shown inFig. 3.

Fig. 6 is a plan. of the twisted tie shown in Fig. 5.

In tying la wire'on a package, the usual procedure comprises passing thewire around the package and disposing the overlapping ends of the wirein close relation in a 1'0- tatable twisting element and in guides orholding members flanking the twisting element. The guides usuallycomprise blocks having alined slots therein, of a height sufficient toreceive the wire, but not suflicient to permit the wires to move bodilyduring the twisting operation. The guides, therefore, serve the functionof preventing the wires from twisting over each other, so that thetwist' is confined between the guides. Disposed between the guides isthe rotatable twisting element which is provided with a slot in whichthe overlapping wires are disposed. The slot is usually narrower at thecenter, its height at that point being substantially the sameas theslots in the guides and for. the same. purpose. At both ends, the slotin the rotatable twisting member is increased in height to provide spacewherein the twist may form. Prior to the twisting operation, the wire isdrawn taut around the package, so that the wire ends lie insubstantially parallel relationship in the grooves in the guides andtwisting member. One form of assembled mechanism for forming twistedwire ties is shown in the co-pending application of myself and O. L.Drew, Serial No. 414,108, filed October 1, 1920, to which reference ishereby made for a disclosure of a complete wire tying device. Thepresent invention, however, is not in any manner limited to the showingmade in such application, since the tie of the present invention may beformed in devices of different structure, and since the tie may be usedfor other purposes, such as for securing togethertwo wires.

The twisting element usually comprises a go. 1' 2 having integral stubshafts 3, suitably journaled in pillow blocks 4, and engaged by adriving gear 5. The gear unit, consisting of the gear and the stubshafts, is rovided with a longitudinal slot 6 exten ing radially fromthe periphery, to and slightly beyond the rotational axis. The depth ofthe slot is preferably such that when two wires are disposedlongitudinally in the slot in close relation, as shown in Fig. 4, thewires lie close to or on opposite sides of the axis of rotation. At itscentral portion the slot is of just sufficient height to rea'tlilyreceive a wire, so that as the gear is rotated the wires at the narrowportion are incapable of relative bodily movement. At the opposite ends,the slot is increased in height, to form two chambers 8 and 9 in whichthe twist is formed. The widening of the slot produces shoulders 12 and13 at opposite ends of the gear unit, which serve as anvils againstwhich the wire is bent as the gear unit rotates. It has been thepractice heretofore, to position these shoulders 12 and 13 di rectlyopposite each other, as shown in Fig. 1, with the result that as thegear is rotated both wires of the twist start to bend at the same pointlongitudinally of the twist. One wire bends u wardly, crossin .over theother wire, and being forced there y against the upper shoulder 12 withgreat pressure, and.

the other wire bends downwardly, crossing under the other wire and beingforced thereby against the lowershoulder 13 with great pressure, thepressures being the bending pressure of the wire and the additionalpressure caused by the opposing pressure of the other wire. The wiresare not only subjected to pressure and torsion, but since they movelaterally in twisting, the shoulders produce a shearing strain. Theseeffects cause the shoulders to bite sharply into the two wires,weakening the wires and consequently weakening the ultimate twist Byvirtue of this construction, also, the convolutions of both i wires,forming the twist, are uniformly axi' all displaced with relation to thelongitudina axis through the gear unit, and experience has proven thatupon subjecting such twist to tension, it will often pull apartorunravel, without breakingthe wire. Such twist as that shown in Fig. 1does not possess a tensile strength equal to or greater than the wireand w en subjected to tension will either rupture at the point ofbeginning of the twist, where the shoulders have mutilated the wire, orwill pull a art, and either of these conditions will usua ly occurbefore sufiicient strain has been placed on the wire to rupture it at anuntwisted portion. If the twist is formed tightly, the biting action ofthe shoulders will materially weaken the wires and if it is formedloosely it will unravel under tension.

;1 -In accordance with my invention, I. form the twist in such mannerthat the beginning of the twist in one wire is spaced longitudinallyfrom the beginning of the twist in the 7 other wire so that theinjurious biting action of the shoulders against the wire is obviated,and so dispose the convolutions of the twist, I that when strained thefull convolutions of each wire pull directly againsteach other. In theconstruction of. gear unit shown in Fig. 2, the upper shoulders 12 arespaced apart a greater distance than the lower, shoulders 13, so thatone wire starts to bend at the shoulder 13- whereas the other wirestarts to bend at the shoulder 12, so that the injurious effect of theshoulders on the wire is minimized.

Substantially the same result isobtained with the form of gear unitshown in Fig. 3, wherein only one shoulder 12 and one shoulder 13 isemployed, the faces of the slot opposite the shoulders being referablysmooth and unbroken. The shoul ers are preferably slightly beveled, asshown at 15, to further lessen the biting eifect on the wire. By thisarrangement of the shoulders, one twist forming chamber 8 is disposedpartly above the axis of the gear unit and the other twist formingchamber 9 is disposed partly below the axis, so that the twists aredisplaced oppositely with relation to the axis of the gear unit and withrelation to the untwisted central portion of the tie. Instead of bothwires being pressed against shoulders at both sides of the untwistedcentral portion, only one wire is pressed against a shoulder and theother wire bears or wears against a smooth surface. I have found thatthe tie formed by the gear unit shown in Fig. 3 is somewhat preferableto the tie formed by the gear unit shown in Fig. 2, although the tieformed by the gear unit shown in Fig. 2 is preferable to the tie formedby the gear unit shown in Fig. 1.

In Figs. 5 and 6, T have shown the twist as formed by the gear unitshown in Fig. 3. The two ends 16 and 16 of the wire are disposed inoverlapping relation and twisted, as heretofore set forth, forming acentral untwisted portion flanked by the twisted portions 17 and 18. llnforming the particular twist shown, the gear unit is rotated through twocomplete revolutions, forming a double twist on each side of the centraluntwisted portion. In the drawings, I have shaded the two wires-16 and16 difierently so that they may be readily identified in the twist. Inorder to produce a tie having the desired qualities, T find it advisableto form the twist in such manner that the initial points of bending ofthe two wires be spaced apart longitudinally. Referring to the twist 17,it will be seen that the wire 16 departs from the straight or untwistedportion at the point B and that the wire 16 departs from the untwistedportion at the point C and that ,the'points B and C are spacedlongitudinally of the tie. The wire 16 bends over the shoulder in thetwisting element while wire 16 wearing against a smooth supportingsurface forces wire 16 over'it, axially displacing the twist from theaxis of the rotating center section. It will be seen that wire 16 cannotcrowd into the initial twisting point B of wire 16 and,

therefore, is compelled to begin its twist fronrnnother point C. Thesame conditions .Qbtain in the twist 18 wherein the wire 16 startsbending at D and the wire 16 starts bending'at E. In the twist 18 (seeFig. 5)

the wires in the convolutions are completely disposed below the plane ofthe uppersurface of the central untwisted wire and in the twist 17 thewires in the convolutions are completely disposed above the lowersurface of the wire in the untwisted central portion.

strain is placed principally on the wire 16 v in the twist 17 and thewire 16' in the twist 18 tending to straighten these wires, and a lesserstraightening strain is placed on the wire 16 in twist 17 and on thewire 16 in twist 18. The humps 23 and 27, therefore, are maintained inform and form abutments against which the abnormal humps 21 and 25 arepulled. This produces a tie which has a greater tensile strength thanthe untwisted wire, due both to the shape of the twist and the fact thatthe wires are not weakened by being cut into by shoulders on thetwisting element. While I have shown two forms of twisting elementswhich may be employed to produce the tie of my inven tion, it is to beunderstood that other devices may be used for producing the tie and thatthe tie is not limited in its formation to any particular form ofapparatus, nor to any form of use or application, nor to any specificnumber of twists, although for band formed ties, the double or tworevolution twist is preferable.

ll claim:

1. The method of securing wires together, which comprises disposing saidwires in overlapping relation, holding said overlapping wires at spacedpoints, rotating the two wires bodily intermediate said held portionswhereby two twists are produced and forming said twists so that onetwist is disposed wholly below the upper surface of the wire at theintermediate untwisted portion and the other twist is disposed whollyabove the lower surface of the wire at the intermediate untwistedportion.

2. The method of securing wires together, which comprises disposing saidwires in overlapping relation, holding said overlapping wires at spacedpoints, rotating the two wires bodily intermediate said held portionswhereby two twists are produced separated by an intermediate untwistedportion and controlling the wires at the junctures of the twists withthe untwisted portion so that the points of initial bending of the wiresat the juncture of a twist and the untwisted portion are spaced apartlongitudinally.

3. The method of securing wires together,

I which comprises disposing said wires in overlapping relation, holdingsaid overlapping wires at spaced points, rotating the two wires bodilyintermediate said'held portions whereby the wires are twisted togethertwist to bend over a shoulder and the other wire to bend over said firstwire.

4. In a wire tying machine, a rotary Wire twisting member, having alongitudinal slot therein adapted to receive the wires to be twisted,one face of said slot being depressed adjacent one end of the member andthe other face of. the slot being depressed adj acent the other end ofthe member, the surfaces of the slot being otherwise unbroken.

In testimony whereof, I have hereunto set my hand.

between the intermediate portion and the held portions, andeausing onewire in each HUGH DE HAVEN, JR.

